AZL Aachen commissions JetBlast system to test battery casings under flame and hot-particle loads

AZL Aachen has commissioned JetBlast, a test system that combines flame exposure with a heated, particle-laden blast to reproduce selected loads acting on battery-casing materials during cell venting and thermal-runaway events. Initial calibration trials have confirmed the benchmark operating point for the Joint Partner Project “Thermal Runaway Testing for Battery Casings,” which AZL launched in 2025. The company says it will complete repeatability and reproducibility checks before participant materials enter the test program.

AZL puts the system’s maximum test-zone temperature at 1,650° C, measured about 5 mm in front of the specimen surface. The current benchmark profile runs a base-and-boost sequence, and in boost mode the target at that near-surface position is 1,300° C before particle blasting begins. Initial calibration trials measured the particle-laden blast at roughly 1,250° C close to the same plane, a differential of about 50° C between the boost target and the blast condition. That differential can be adjusted through the operating settings, and the company says its stability and reproducibility will be documented in the released calibration protocol.

Cold carrier air can cool a specimen that has already been heated and distort the intended combination of thermal and erosive loading, and AZL says JetBlast reduces that blast-induced cooling.

Rather than adapt a commercial torch, the company built its own burner and particle-injection architecture, coordinating flame temperature, particle temperature, particle mass flow, blast intensity and exposure time in one configurable sequence.

JetBlast is the third method family in AZL’s fire testing for battery enclosures. The first measures material strength during fire exposure under a defined tensile load. The second comprises custom torch-and-grit and particle-blasting methods developed for OEM and tier-supplier programs.

Outputs can include exposed- and backside-temperature development, time to threshold or burn-through, material integrity, damage area, mass loss, cracking or delamination, continued burning and failure modes, rather than a single pass-or-fail result. AZL describes JetBlast as a screening and development method for selected thermal and particle-impact loads that does not replace cell-, module-, pack- or vehicle-level testing under GB 38031-2025 or UN Regulation No. 100, and it does not generate pack overpressure.

Testing of two participant-selected materials or material configurations per participant is included in the standard project offer, and companies can join until September 2026.

“The objective is not to imitate one cell event once. It is to identify the damage-driving loads, reproduce them in a controlled profile and use the evidence to match the material, protection concept and casing architecture,” said Ravi Chaitanya Bhairi, AZL’s Head of testing" class="tag-link text-primary font-medium">Fire Testing for E-Mobility.

Source: AZL Aachen